This invention relates generally to mechanical linkages and particularly to a temperature stabilized linkage particularly adapted for use with an airplane stabilizer and elevator.
The present invention is particularly designed for use with a tail assembly of a modern jet plane. The tail assembly may include a horizontal stabilizer and elevator adapted to be rotated out of the plane of the stabilizer.
Recently attempts have been made to manufacture the stabilizer of a composite material while retaining the presently used aluminum elevator. Due to the difference between the coefficients of thermal expansion of aluminum and a composite structure various problems arise.
One attempt was made to retain the existing aluminum trailing edge beam and fiberglass trailing edge panels of the stabilizer. This, of course, minimizes the differences of the thermal expansion at the elevator hinges. However, it has been found that many pieces of special hardware would be required to support the trailing edges. Also the trailing edge components required more extensive revision than initially anticipated.
The second approach was to use graphite epoxy trailing edge beams, as well as a composite material stabilizer. This, of course, minimizes thermal stress and deformation in the trailing edge structure of the stabilizer. On the other hand, the thermal expansion differences at the elevator hinges become much greater.
Therefore, a temperature compensated linkage was designed to compensate these thermal differences.
Such a thermal compensating structure member has been disclosed in the patent to Belew U.S. Pat. No. 3,675,376. This structural member is used in an antenna structure and includes an aluminum casing and a titanium casing which will expand differentially. This in turn will rotate a link 44 to compensate for effects of changes in temperature.
Reference is also made to a patent to Broders et al., U.S. Pat. No. 3,327,552 which also discloses a temperature compensated linkage. It is to be used for the turbine engine parts of an aircraft engine. Here one of the supporting structures is moved with respect to another. The linkage is so designed as to compensate for the rather violent temperature changes of a turbine engine.
The novel features that are considered characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, as well as additional objects and advantages thereof, will best be understood from the following description when read in connection with the accompanying drawing.